Proteins have a variety of functions within the body that include stimulatory, catalytic, transport, structural and molecular sequestering activities. The definition of functional proteins varies among different scientific disciplines. Functional proteins can be defined as proteins that when fed to animals improve animal performance and well-being beyond what can be explained solely by our understanding of nutrition.
Spray-dried plasma (SDP) is a functional protein source that has considerable peer reviewed research describing its beneficial impact on immune response and barrier function when fed to animals. Spray-dried plasma consists primarily of albumin, globulins, fibrinogen along with lesser quantities of other proteins or peptides. As used herein the term “plasma” shall include the plasma portion of blood as well as any of the protein components which may be further purified therefrom. Purifications of these components from plasma are methods known and commonly practiced by those of skill in the art.
Numerous studies involving challenge or natural infection with pathogenic bacteria, viruses, or protozoa have reported reduced mortality and/or improved health indices in a variety of species (swine, calves, poultry, and shrimp) fed diets containing spray-dried plasma proteins. Although spray-dried plasma contains globulin protein, (Borg et al., 2002) antibody neutralization of antigens in the gut lumen does not fully explain the improvements noted in animals fed plasma proteins.
Spray-dried plasma proteins are used extensively in nursery pig feed to enhance feed intake, growth, and feed efficiency during the post-weaning period. Scientific reviews of published research clearly show that addition of spray-dried plasma to pig diets at weaning increases feed intake, growth rate, and improves feed efficiency (Coffey and Cromwell, 2001; Van Dijk, 2001; Torrallardona, 2010).
The nutrition provided by SDP in gestating sow feed can support litter performance (Crenshaw et al., 2010). Primiparous sows provided a gestation diet containing SDP from day 14 of pregnancy to farrowing had heavier pigs at birth, fewer pigs weighing less than 1 kg at birth, and both primiparous and multiparous sows had pigs that were heavier at 18 d of age compared to sows provided a diet without SDP. Similar results were observed in a pregnant mouse model of transport stress in which mice provided nutrition from diets containing SDP had increased pregnancy rate along with larger litter size and heavier average fetal weight near the end of pregnancy compared to mice provided a diet without SDP (Song et al., 2012 a,b).
Heat stress reduces feed intake of lactating sows and pig weight at weaning (Spencer et al., 2003; Safranski et al., 2010). Several studies reported that the nutrition provided by SDP in lactation diets support sow and litter performance, particularly if fed during summer months (Crenshaw et al., 2007, 2008; Van Iersel et al., 2011). In these studies SDP in lactation diets contributed to improved pig survival to weaning, heavier litters at weaning, greater feed intake by young sows, reduced wean to estrus interval of primiparous sows, and increased farrowing rate of sows to the next lactation compared to a lactation diet without SDP.
Collectively, these studies demonstrate that the enhanced nutrition provided by SDP in diets support sow productivity indices, including pig survival and pig weight gain to weaning, particularly during periods of stress associated with summer heat.